sewall



(No Model.) 2 Sheets-Shee1; 1.

M. W, SEWALL. I MECHANISM FOR AUTUATING SHUT-OFF AND THROTTLE VALVES.

No. 430,090. Patented June 10, 1890.

WITNESSES. J NIOR ATTORNEY 2 Sheets-Shget 2.

ALVES. Patented June 10, 1890.

(No Model.) v

M. W. SEWAL'L'.

MECHANISM FOR AGTUATING SHUT-OFF AND THROTTLE V 1%.. 430.090

A Tram/51% v If w a K W W a I I igzyroze. 2/: var-d UN rrn STATES MINOTT\V. SElVALL, 0F NEXV YORK, N. Y.-

MECHANISM FOR ACTUATING SHUT-OFF AND THROTTLE VALVES.

SPECIFICATION forming part of Letters Patent No. 430,090, dated June 10,1890.

Application tile-d December 11, 1888. Serial No. 293,298. (No model.)

To all whom it may concern.-

Beit known that I, MINoTT W. SEWALL, a citizen of the United States,residing at the city, county, and State of New York,have inventedcertain new and useful Improvements in Mechanism for Aotuating Shut-Offand Throttle Valves, of which the following is a specification.

This invent-ion relates to piston-valves, annular valves, disk-valves,or other forms employed to shut off or to throttle the flow of fluidsubject thereto and actuated for said purpose by the application of apressure or of opposing pressures applied to a part of said valvesexposed in an independent chamber or chambers.

The invention is especially applicable to stop-valves employed to admitor retard to a certain degree the delivery of firing-fluid from thereservoirs to the gun-barrel of a pneumatic gun, said valves remainingopen at a fixed point during the gun action, while the intermission ofdischarge is controlled by the usual separate firing-valve employed inconj nnction therewith.

The object of the invention is to obtain a positive control over thevalve-movements and to facilitate the handling of valves, especially oflarge size, controlling a high degree of pressure or a large volume offluid, and to enable others skilled in the art to construct a mechanismfor the purpose.

I do not herein claim the method of controlling the gas-movement andregulating the same, such method being claimed in an application of evendate herewith, to which the Patent Office gives the serial number293,297.

In its use as a throttling-valve in conjunction with an automaticdischarge-valve, as the firing-valve of a pneumatic gun, the herein-described throttling adjustment is employed-to determine thedischarge-valve-de livery capacity, thereby extending the range ofadjustment applied to the latter.

In order to enable others to understand and use my said invention, Iwill proceed to describe the details of construction of certain forms ofvalves herein instanced as adapted to carry the invention into practice,explain their operation, and to subsequently point out in the appendedclaims the features which I claim as new.

ing the invention as applied to an annular valve; and Fig. 3 a sectionalelevation illustrating also an annular valve, but embodying the featureaforesaid of providing a straightway fluid passage through the casing.

Similar letters of reference indicate parts having correspondingfunctions throughout the views.

A, Fig. l,is a triple-piston automatic valve wherein the interior orcentral piston F composes the valve proper and the exterior ones G H areemployed to balance and also to actuate the said interior piston-valve.

B is the inlet, and C the outlet, port, the functions whereof are,however, capable of reversal.

D E are the actuating-chambers, wherein the hydraulic motive power isapplied to actuate the valve A in either direction, said chambers havingpipe-conn ections a and cocks b, as three-way cocks, adapted toalternately charge or discharge through said pip-econnections bypressure-pipes c and exhaustpipes d.

The actuating-pistons G H are packed, preferably by cup-leatherpackings, turned in opposite directions to resist pressures from bothways, and the piston F, provided with similar packiugs in itscircumferential seat turned in a common direction toward theinlet-pressure. Otherwise, as in steam-controlling valves, expansivemetallic packingrings may be employed.

P is an indicator, operated over the scale 19 by the small piston-rod qto indicate the extent of valve-opening and enable the operator toadjust the same at any desired point.

I is a deflector, (open at f,) adapted to direct the current ofsubject-fluid and lessen its friction-as far as practicable.

In Figs. 2 and 3 the annular valves A are projected or retracted to orfrom their seatingpoints, moving between the interiorly-circumferentialcores J and the eXteriorly-circumferential cylinders K by the alternatecharge or discharge of oppositely-applied pressures in chambers E and D,respectively. The

means of applying said pressures in both instances corresponds with thatdescribed in reference to Fig. 1, as will be understood by an inspectionof said Figs. 2 and 3. The passages a, which communicate to chambers Dinterior to the valve annulus being adapted to extend thereto throughthe central stationary cores J, as through the cavity L, in the instanceof Fig. 3, wherein said passages are located through the webs M, asshown. The cup-packings are provided, as shown, upon all the movingsurfaces at the portions which separate the several chambers.

. The novelty in Fig. 3 consists in supporting the entire valvestructure (with its actuating-chambers) within and centrally to theouter casing by means of Webs M, ranged radially between said casings inany desired number, connecting the same together preferably in a singlecasting. An annular passage for the subject-fluid or a series ofpassages is thereby formed around the valve, permitting the currents topass in as nearly a continuous direction as attainable with this form ofvalve. The tapered heads N O of the interior casing assist to divide thecurrents flowing in either direction, as the case may be, when the valveis open.

In operation, the pistons F H, Fig. 1, are balanced when the valve isclosed by the surrounding pressure in B, and when open the pressurethattakes place in chambers C 0' likewise balances between F and G, allthe piston diameters being equal. The valve as a whole being thusinteriorly balanced, is capable of being moved in either an opening or aclosing direction by predominant pressure in chamber D or E,respectively, the operator observing and adjusting such movements underpositive control by means of the indicator P and valves 1) b, andlocking said movements when the desired adjustment is obtained by themeans aforesaid of intercepting the actuating-liquid. The valves, Figs.2 and 3, are

free from pressure of the subject-fluid (in the direction of movement)when seated, and are therefore held in said position by equal pressuresin D and E, predominant on the greater area in E. \Vhen E is released,pressure in D performs the opening stroke. The pressure in E may be lessin degree than the subject-fluid, but it must be sufficient upon thegiven excess of area to overcome the pressure of the subject-fluid (uponthe seating end of the valve) for the purpose of returning the valve toits closed position. It will therefore be understood that in practice Imay employ a low actuating-pressure for effecting the control of asubject-fluid under high pressure. The latter feature applies to allvalves con structed and actuated under the herein-described system.

It is to be understood that I do not limit my invention to the specificforms herein cited; but I claim, broadly 1. A valve for pneumatic cannonhaving a throttle or stop in the main fluid-passage from the reservoirto the gun-barrel, two pistons connected to said throttle or stop andworking in chambers, separate pipe-connections leading to thesefluid-chambers, whereby the pistons therein maybe actuated andcontrolled, and an indicator connected to the main piston to show itsposition, all combined substantially as described.

2. In a valve for pneumatic cannon, the combination of athrottling-piston in the main passage from the reservoir to thegun-barrel, two controlling-pistons connected with said throttle andworking in chambers, a separate fluid-passage to eachcontrolling-chamber, and a deflecting-guide in the main passage by whichthe subject-fluid is in part guided in its course to or from thethrottle.

MINOTT WV. SEW'ALL.

WVitnesses:

CHAS. WV. FORBES, J OHN A. ELLIS.

